Field
The present invention generally relates to an electric motor used to provide power to drive an electric power tool such as an electric disc grinder. More particularly, embodiments of the present invention relate to a rotary electric motor with rotor positioned lengthwise within a tubular stator.
Background Art
Electric motors configured to power portable tools may generally include a rotor positioned lengthwise within a tubular stator. Several relatively thin laminated steel sheets may form a core of the stator. The stator may also have several electric and/or magnetic coils, each of which may be wound in a loop shape and be positioned, for example, to face other coils. Further, an insulating member made from resin, for example, may be attached to both ends of the stator core. Moreover, a lead wire may connect to each of the coils through the insulating member. The lead wire may be inserted into a corresponding insertion port located in the insulating member to electrically connect to an end part of one or more coils as described above. The lead wire, connected to the coils, may be fixed to the stator at a position near the insertion port to, for example, prevent the lead wire from inadvertently slipping off and to otherwise maintain a stable connection state between the lead wire and the coils. Conventionally, to fix the lead wire to the coils of the stator, the lead wire may be bundled with a string. However, the bundling of the lead wire with a string may be troublesome, time-consuming and/or otherwise add to the overall complexity of using the electric motor. For example, Japanese Laid-Open Utility Model Application No. S62-132651, which relates to a simplified technique for holding a lead wire, may use a lead-wire-holding member located in an insulating member where the lead wire may be held along an inner circumference of the stator core. Further, the aforementioned Japanese Laid-Open Utility Model Application No. S62-132651 may also disclose that a holding member for holding the lead wire such as a clip may be attached to a side of the stator core to holding the lead wire.
However, according to the lead-wire-holding structure as discussed above, one or more lead wires may be held along the inner circumference of the stator core, thus contributing toward crowding and/or cramping of the lead wires along the wiring path. Such crowding of the lead wires along the wiring path as described here may add to the overall complexity and/or difficulty of operating the electric motor. Moreover, space occupied by the stator core may increase proportionate to the width of the lead-wire-holding member that attached to a side of the stator core, as described above. Thus, the resultant bulk of the stator core with the lead-wire-holding member attached thereof may impair movement and/or manipulation of the stator with respect to a case of an electric power tool. In view of the difficulties in operating a bulky stator core as described, there is a need in the art to permit for convenient attachment of lead wires to the stator core without increasing the overall bulk of the stator core. Also, there is a need in the art to simplify the work needed to hold the lead wire and/or other wiring components associated thereof to the stator.